The present disclosure relates generally to an electrophotographic system, such as a xerographic system, and more particularly to an improved trickle collection system and method for an electrophotographic system including a trickle port and trickle port housing communicating the interior of a developer housing with a vacuum collection source.
Electrophotographic methods and apparatus are well known. FIG. 1 schematically illustrates an electrophotographic apparatus. As shown therein, an electrophotographic apparatus generally includes an imaging portion for generating an electrostatic latent image on an image bearing member, such as a recording sheet or media, a developing portion for applying toner to the latent image to develop the image on the image bearing member, and a fixing portion for fixing the developed toner image on the image bearing member.
Image developing systems including developer cartridges and developer are well known. A known developer includes a combination of magnetizable carrier particles, such as steel beads, and non-magnetic toner particles. The carrier particles are transported by mechanical means and magnetic fields that move within the developer cartridge housing. In a developing process, toner particles adhere to carrier particles by triboelectric charging due to friction between the particles during agitation and transport in the developer cartridge housing. The carrier particles transport toner particles to a developer transfer region and apply the toner to an image bearing member, such as a recording sheet or media. As toner is consumed in the developing process, the developer cartridge housing is replenished with new developer including carrier particles and toner particles. Over time, carrier particles become impacted and are altered due to the harsh environment in the developer cartridge housing. These impacted/altered beads are discharged as trickle from the developer cartridge housing via a trickle port formed in the housing.
FIG. 2 is an exploded perspective view of a known developing system 100 for an electrophotographic system. As shown therein, the developing system 100 is a four stage developing system generally including four developer cartridges 110 for respectively developing images with magenta (M), yellow (Y), cyan (C) and black (Bk) developer, and a trickle collection system 120. The trickle collection system 120 generally includes a trickle collection tree 122 and a trickle collection bottle assembly 124. The trickle collection tree 122 generally includes four inclined branches 126 (M, Y, C and Bk), and a plurality of vertical stems 128, 130 and 132 connecting the branches 126 to the trickle collection bottle assembly 124. Each branch 126 generally includes a trickle port 134, a trickle collection funnel 136 and a Y-connector 138. Each trickle port 134 (M, Y, C, Bk) is provided in a developer housing wall of a respective developer cartridge 110 to communicate the interior of the developer cartridge housing 152 with the exterior, to permit gravity feed of trickle output by the developer cartridge 110 via the trickle port 134 to a respective trickle collection funnel 136 of the trickle collection system. Trickle collected by each trickle collection funnel 136 in turn is gravity fed through a respective branch 126 and the vertical stems 128, 130, 132 of the trickle collection tree 122 and collected in the trickle collection bottle assembly 124.
Known trickle collection systems have a number of drawbacks. Gravity feed trickle collection systems are prone to blockage or bridging of trickle due to various factors including collection angle, humidity and material state changes. The angle of repose of developer material typically is around 38-55 degrees. Changes in external humidity or internal conditions affecting the developer can aggravate this limitation. Accordingly, gravity feed trickle collection system elements must be arranged in locations and with orientations that facilitate gravity feed, that is, generally vertically depending from developer cartridge housings.
A gravity feed collection system also requires an auger system to deposit trickle gathered by a trickle collection tree into a collection bottle. Such trickle collection systems require a user or customer service engineer to stop production of prints in order to replace the collection bottle when it is full. Such auger systems have a drawback due to leakage at auger interfaces and worn seals.
Known electrophotographic systems also have drawbacks related to size, shape and orientation requirements. For example, electrophotographic systems that use multiple developer cartridges must stack or otherwise arrange the developer cartridges and may have substantial size requirements and other limitations (e.g., height and footprint limitations). These size requirements and other limitations may impose restrictions on the location of trickle ports on the developer cartridge housing and the trickle collection system elements within the electrophotographic apparatus. Variations in mounting orientations (horizontal orientation) of developing cartridges due to individual internal mounting tolerances and external factors, such as the support surface, also may impose restrictions on the location of trickle ports and trickle collection system elements. Generally, apparatus size and shape restrictions/limitations are determined to satisfy user needs and desires.
Thus, a need exists for an improved trickle collection system and method that overcomes these drawbacks of known electrophotographic systems and trickle collection systems and methods. In particular, a need exists for an improved trickle collection system that reduces the impact of size and orientation restrictions of a developer cartridge and accommodates user needs and desires for a compact electrophotographic system.